Common to the bicyclic structures of both penicillins and cephalosporins is the .beta.-lactam or azetidinone moiety. Because of the significance which microbioligists have attributed to the presence of the .beta.-lactam entity in the structure of these active antibiotic compounds, many chemists in search of new antibiotic compounds have used the .beta.-lactam ring system as a nucleus from which to carry out their research. Of course, there have been many new .beta.-lactam intermediates, both monocyclic and bicyclic, resulting from such research efforts and from similar research efforts directed to penicillin-cephalosporin conversions. Many such intermediates have been derived from penicillins and cephalosporins; others have been prepared by totally synthetic means.
This invention relates to certain monocyclic azetidinone mercury sulfide intermediates, useful in the synthesis of cephalosporins derivatives, and to a method of preparation of such intermediates from penicillin sulfoxide derived bicyclic thiazolineazetidinones.